I am sure they are fine and will play for 50 hours on one charge.
But aren't they a bit pricy at 135USD ?
In any case you need need 4 sets of batteries for two channel balanced, as they all swing different voltages.

I have zero knowledge about anything tube.
Paul (needsp) would be the man to ask, I guess.

> I did not use the famous heatsinks and got the output stable at less than 2mV.

The famous heat sinks keep the temperature down for the 2SK369Vs running at 20mA for higher reliability.
They also keep the DC offset at the input close to zero, and not at the output.
Kirchoff's law takes care of the output.

That is because you spread the heat into 3 FETs instead of one 2SK369V.
So you might get away without using heat sinks.

In our own measurements, we think that you will need to use 4x 2SK170BL to replace two 2SK369V for the same transconductance.
But then maybe a few ohms extra Zin is not so important.
Afterall, you are happy with the sound ? That's all matters.

As to copies of our work, our position remains the same.
The circuit is public property. Anyone can copy.
And we are genuinely pleased that you take the trouble to make a custom PCB for your own use.
But we as a matter of principle will not endorse anyone else's PCB layout other than our own.

Hope you will understand.

All these discussions will be irrelevant once we release our ES9018 integrated solution.
This will have everything on board, including regulators or passive power supply filters, XO's,
IV circuit, battery connections , SPDIF AND USB input for 32/384.

All these discussions will be irrelevant once we release our ES9018 integrated solution.
This will have everything on board, including regulators or passive power supply filters, XO's,
IV circuit, battery connections , SPDIF AND USB input for 32/384.

Will take time. Good things cannot be rushed.

Cheers,
Patrick

I'm extremely interested, please do keep us up to day on any progress..

Great work! I think placing the SEN/CEN I/V below the Buffalo II/III will improve very significantly the implementation of the SEN/CEN circuit with the very popular TPA variant of the ES9018 DAC. Mine is a terrible wire clutter...

I am convinced that a SEN/CEN/ES9018 solution from Patrick and co. will be very good. Just a petty that many, less skilled DIY'ers, who have already spend a significant amount of money on the Buffalo have no "easy" way of trying out the SEN/CEN circuit.
Really a shame, as the SEN is a very significant better I/V than what most are currently using.

> I think placing the SEN/CEN I/V below the Buffalo II/III will improve very significantly the implementation of .....

It is the most terrible place you can put an analog circuit with a power supply that swings with the signal.
Guaranteed to pick up all the garbage from the digital circuitry running at 98MHz.

I do not understand why a few twisted wires for the current out and 2 resistors to make up a Vref is such a difficult task.
A convenient PCB layout does not necessary make a good layout in performance terms.

I understand you do not want to go through the hassle of a group buy...but could you publish the layouts in a way I can ask a pcb-service to produce it for me ?

THX

Hi Blitz,

It's not about the hassle of a group buy (check my GB for the DIY Curve Tracer to see I'm not afraid of that !.... that one would be piece of cake) it's about respect of intellectual property as EUVL expressed it. There is a commercial product for the SEN/CEN and I do not want to interfere with that.